The development of the precautionary principle by the EU Courts has often been interpreted by scholars as inconsistent with another trend in EU risk regulation: one that is evidence-based and relies on impact assessment. This article argues that the two trends – precaution and regulatory impact assessment – are not mutually exclusive. Together they may, in fact, act as a procedural safeguard against discretionary decisions that have an impact on fundamental rights, especially under conditions of epistemic uncertainty. The article illustrates this claim by looking at the decisions to close schools in Ireland during the pandemic.